Technical Field
The disclosure relates to a battery, and specifically to a battery having an improved stack design for compact profile and ease of manufacturing.
Related Art
Batteries are commonplace in a wide variety of electrical applications. Improvements in battery packaging efficiency are constantly being sought in order to reduce device size, as well as to allow for more active material to be inserted into an allotted volume to achieve better longevity and performance. This is particularly true in implantable medical devices (IMD's) such as implantable cardioverter defibrillators (ICD's) where physical size is a critical design element. In many IMD applications, the battery occupies a significant portion of the overall IMD volume. In order to minimize the size of the IMD, it is desirable to minimize the size and/or maximize the energy density of the battery.
Batteries are commonly manufactured in a rolled cell format (sometimes referred to as a “jelly-roll”). In this format, a long anode and a long cathode are brought together and rolled into a cylinder to create the battery stack. Because of the simplicity of this packaging method, it requires very little manufacturing and is therefore a low cost solution. However, its cylindrical shape can be inefficient in space-constrained applications such as IMD's. Specifically, when used in a rectangular package format, the cylindrical battery wastes large portions of space within the device.
As a more space-efficient alternative to the rolled cell format for applications such as IMD's, a stacked cell format may instead be used. The stacked format requires multiple cathode assemblies and multiple anode assemblies to be alternately stacked on top of one another. The multiple cathode assemblies must then be welded together along an edge of the stack, and the multiple anode assemblies must be welded together along another edge of the stack. Consequently, although this design provides greater space efficiency, it requires more parts and more assembly, making it more costly and complex to manufacture.